Clamp device



CLAMP DEVICE Filed Aug. 23, 1939 z venas. zdwardx. fllen.

arold J.' Hill.

Patented Dec. 23, 1941 'Edward R. Chilcott,

Glendale, Harold Jl. Hill,

North Hollywood, and Walter H. Righter, Glendale, Calif., assignors, by mesne assignments, to Medical Engineering Calif., a co-partnership Knox, T. Keith Glenn Hickson Company, Los Angeles,

composed of Stuart C.

an, and Daniel Cornwall 'Application August 29, 1939, serial N6. 291,566

6 Claims.

This invention relates generally to clamping devices, and more particularly to clamping devices adapted for quick manual application to a rod or shaft. The clamping device of the present invention is adapted particularly for use in connection with a fracture frame which is the subject matter of a copending application of Stuart C. Knox entitled Fracture frame, filed August 1, 1939, Ser. No. 287,779, now Patent No. 2,239,821, dated April 29, 1941, and will be described in a specific form especially'designed for that particular application; it will of course be obvious, however, that the device of the present invention is adaptable to a variety of uses other than the illustrative application to fracture frames, and no limitation to any particular type of use is therefore to be implied.

In the fracture frame disclosed in the aforesaid copending application which is now a patent, there arev provided a number of cross bars` each havinga clamping device at each! end by Fig. 1 shows a pair of clamp devices in ac cordance with the invention, mounted at opposite ends of a tubular rod and clamped to a pair of parallel vertical rods or shafts;

Fig. 2 is an elevation of one of the clamp devices, showing the clamping sleeve in released which it may be clamped between parallel rails or rods of the frame.V It is desirable that the clamping device employed for clamping these cross bars to 'the members of the frame be of a quick attachable and detachable type, and that they be capable of being set up very tight without the application of great'manual exertion.

The general object of the present invention is therefore to provide an improved form of clamp for such typical uses as clamping a bar or other member to a rod or shaft, `.which is capable of being applied or removed by `a simple manual operation, and which is capable of being manually set up to exert'a comparatively tight gripping force, but without requiring great manual eX- ertion. Y Y

'I'he clamp device provided by the present invention embodies two clamp parts, hinged together, and adapted. to surround the shaft to which the clamp device is to be applied. One of these clampV parts is on the end of a shank, aroundwhich is a rotatable clamping sleeve. The other of the clamp parts has a lug whichr is overridden by an eccentric or cam surface inside of the clamping sleeve. Rotation of this sleeve brings its cam surface lto bear Vwith gradually increasing pressurev on this lug, and so compresses the clamp part having the lug radially inward. The cam surface is preferably relatively long, though of small pitch, and great clamping force is accordingly exerted with relatively small twisting force on the sleeve.

The invention itself will be understood by now referring to the following detailed description of position;

Fig. 3 is a section taken online 3-3 of Fig. 2;

Fig.,4 is a view similar to Fig. 3, but showing the device in fully clamped position;

Fig. 5 is a section on line 5--5 of Fig. 4; and

Fig. 6 is an end view of the clamp, being taken in the direction of arrows 6-6 in Fig. 2.

In the drawing, numeral l0 designates generally a tubular rod or bar, having mounted on its opposite ends clamp devices I I in accordance with the present invention. The ola-mp devices I I are shown as applied to a pair of parallel, vertical rods or shafts I2. These vertical rods l2 may be regarded as a pairV of vertical cross bars of the fracture frame of the aforementioned co' pending application now a patent, the member I 0 being a cross bar which is clamped Vto and between vertical members I2, and which may be employed as a load sustaining member, thus making necessary that the clamp devices have non-slipping engagement with the vertical members .|2. Fig. 1 of course shows merely one typical use and application of the clamp device of the present invention, no limitation to 'fracture frames being implied; however, the arrangement of Fig. 1 is nicely illustrative of typical uses to which the invention is adaptable.

The clamp device Il has, in the specific form here chosen for illustration, a cylindrical shank i3 received within the end of tubular member lo. Integrally formed with this shank I3, and disposed beyond the end of tubular member IU,

' is a substantially semi-cylindric clamp portion or strap I5, adapted to lit approximately half way around the member I2 to which the Vclamp is applied.. Hinged to member i5, as Vby means of hinge pin I6, is a substantially semi-cylindric vclosure strap I7. The inner surfaces of the members I5 and Il when in closed position denne a substantially cylindrical opening i3 within which the member l2 is received. Member I? is adapted to swing open `on hinge pin l to the position illustrated in dotted lines in Fig. 3 to permit the device to be applied to the member I2, after which member I1 is swung to its closed position as illustrated in full lines in Fig. 3.

the shank is cut away on the side opposite strap member I5, forming a surface 25 flush with th-e end of tubular member I0, the surface 25 being connected with the inner surface of strap member I by an inclined surface 21. A locking lug 28 projecting from the hinged closure strap I1 is received in the space so provided, its end facing surface 25 when the yclosure strap is closed, and its inclined under surface 29 being presented in opposition to surface 21, but being normally spaced somewhat therefrom (see Fig. 3).

The enlarged portion 213 of shank I3 terminates in a shoulder 23a formed in a plane transverse to the axis of tubular member I0, and closure strap I1 has, around lug 28, a shoulder I'fa coplanar with shoulder 23a.

A clamping ring or sleeve 33 is rotatable on the end of tubular member ID and on shank portion 23, between shoulders 23a and I1a and the end of a pin 32 extending through tubular member I0 and shank I3, pin 32 being set tightly in tubular member I0, while the bore Illa in shank I3 through which pin 32 projects may, in some instances, be made somewhat oversize, for a purpose presently to be explained. The end portion of rotatable clamping sleeve 33, that is, the portion that overrides lug 28, has an internal eccentric or cam surface 35, and also has a notch 36 adapted to pass lug 28 when positioned in alinement therewith (see Fig. 2). As illustratively shown in Fig. 5, this surface 35 is eccentric to shank I3, and is preferably comparatively long, so as to afford a powerful inward wedging action on lug 28. For the purpose of the claims the expression cam will be adopted as generic to either cam surfaces of special shapes or true eccentric surfaces, it'being evident that even when the surface 35 is a true eccentric, it nevertheless functions as a cam.

The clamp device being in the position of Figs. 2 and 3, rotation of sleeve 30 to the position of Figs. 4 and 5 causes ca-m surface 35 to engage and bear inwardly against the surface 31 on the outer side of lug 28, the locking sleeve thus becoming tightly wedged against lug 28 so that it is restrained against displacement by the frictional engagement with said lug. This causes the clamp member I1 to be moved inwardly against the rod I2, the member I1 being capable of movement from the full line position of Fig. 3 to the position of Fig. 4, at which time opposing surfaces 21 and 23 on the members I5 and. i1 would come into engagement, thus limiting further inward movement.

The long cam or eccentric surface 35 permits great force to be exerted against the gripped rod I2 without application of a great amount of manual exertion.A Furthermore, when the locking sleeve 30' is set up, the frictional engagementv between the inter-engaging surfaces'35 and 31 on the locking sleeve and lugis such that accidental release will not occur. On the other hand, only a small degree of exertion is required to release the locking sleeve from its frictional locking engagement with the lug 28. Thus the clamping device may be very tightly clamped to or released from the rod I2l with the application of but comparatively slight twisting pressure, being easily operable with the fingers.

A stop lug 44 formed on sleeve 3IJ engages pin 32 when locking lug 23 is in alinement with aperture 35, this provision enabling the position at which the clamp device may be opened to be readily found.

VIt was previously mentioned that the transverse aperture |311. through which pin 32 projects is preferably or in some cases made somewhat oversize, thus permitting shank I3 some degree of longitudinal as well as rotative movement within 'the end of tubular member I0. This provision enables the cross bar to be more readily clamped between two longitudinal members such as I2 which are a fixed distance apart, it being apparent that if no such play were provided, the slightest difference in distance from center to center of the members I2 and from center to center of the clamp devices at the two ends of the connecting member I0 would bring about difculty in applying the clamps. The feature of a clamp device loosely mounted on the end of a rod as incorporated in a fracture frame is claimed in the aforementioned application of Stuart C. Knox, Ser. No. 287,779.

It will be understood that the drawing and description are for illustrative purposes only, and that various changes in design, structure and arrangement may be made without departing from the spirit and scope of the invention or of the claims appended hereto.

We claim:

1. A clamp for rods and the like comprising two strap members defining a rod-receiving opening, a hinge connection between corresponding ends of said strap members, a shank on the opposite end of one of said strap members extending transversely of said rod receiving opening, a locking sleeve rotatable about said shank, means confining said sleeve against substantial longitudinal movement on said shank, a portion of said sleeve at its end adjacent said strap members being formed with an internal radially acting lcam surface, a lug projecting from the other of said strap members adapted to be received within the end portion of said sleeve and to be engaged by said cam surface, and said sleeve having a notch adapted to pass said lug in one position of rotation of said sleeve.

2. A clamp for rods and the like comprising two strap members defining a rod-receiving opening, a hinge connection between corresponding ends of said strap members, a shank on the opposite end of one of said strap members extending transversely of 'said rod receiving opening, a tubular member mounted on said shank, said shank having an venlarged section of the same diameter as the exterior diameter of said tubular member between the end of said tubular member and said strap member, a locking sleeve rotatable on said tubular member and on said enlarged section of said shank, a portion of said sleeve overlying said enlarged section of said shank having an internal cam surface, a portion of the enlarged section of the shank being cut away on the side opposite said strap member, and a lug projecting from the other of said strap members and received within the space so provided and within the end portion of said locking ring, said lug being operatively engaged by said cam surface.

3. A clamp for rods and the like comprising two strap 'members defining a rod-receiving opening, a hinge connection between corresponding ends of said strap members, a shank on the opposite end of one of said strap members extending transversely of said rod receiving opening, a tubular member mounted on said shank, said shank having an enlarged section of the same diameter as the exterior diameter of said tubular member between the end of said tubular member and said strap member, a locking sleeve rotatable onsaid tubular member and on said enlarged section of said shank, a portion of said sleeve overlying said enlarged section of said shank having an internal cam surface, a portion of the enlarged section of the shank being cut away on the side opposite said strap member, and a lug projecting from the other of said strap members and received within the space so provided and within the end portion of said locking ring, said lug being operatively engaged by said cam surface, and said sleeve having a notch adapted to pass said lug in one postion of rotation of said sleeve.

4. A clamp for rods and the like comprising two strap members defining a rod-receiving opening, a hinge connection between corresponding ends of said strap members, a shank on the opposite end of one of said strap members extending transversely of said rod receiving opening, a tubular member mounted on said shank, said shank having an enlarged section of the same diameter as the exterior diameter of said tubular member between the end of said tubular member and said strap member, a locking sleeve rotatable on said tubular member and on said enlarged section of said shank, the strap member associated with t e shank having a shoulder confining said sleeve against longitudin-al movement toward said strap member, and means for confining the sleeve member against substantial longitudinal movement in the opposite direction, a portion of said sleeve overlying said enlarged section of said shank having an internal cam surface, a portion of the enlarged section of the shank being cut away on the side opposite said strap member, and a lug projecting from the other of said strap members and received within the space so provided and within the end portion of said locking ring, said lug being operatively engaged by said sam surface.

5. A clamp for rods and the like comprising two strap members dening a rod-receiving opening, a hinge connection between corresponding ends of said strap members, a shank on the opposite end of one of said strap members extending transversely of said rod receiving opening, a mounting member having a tubular end portion in which said shank is received, said shank and mounting member being associated for relative longitudinal and rotative movement, means limiting such relative longitudinal and rotative movement, said means comprising a pin set tightly in and extending transversely through said tubular end portion of said mounting member and an oversize aperture in said shank receiving said pin, a locking ring rotatable about said shank, an internal cam surface on said ring, and a lug projecting from the other of said strap members adapted to be received within said ring and operatively engaged by said cam surface.

6. A clamp for rods and the like, comprising a contractible strap means deiining a rod-receiving opening and having two opposed ends adapted to be moved relatively toward each other to clamp a rod in the opening, a shank on one end of the strap means extending transversely of the rod receiving opening, a locking sleeve rotatable about the shank, a lug projecting from the other end of the strap means and adapted to be received within the end portion of the sleeve adjacent the strap means, the sleeve having a notch adapted to register with and pass the lug in one position of rotation of the sleeve, the inner surface of the sleeve adapted to engage an outer surface of the lug, and one of said engaging surfaces being provided with a cam formation extending circumferentially of the sleeve, whereby rotation of the sleeve from its position in which its notch registers with the lug forces the lug toward the shank and contracts the strap means.

EDWARD R. CHILCO'IT. HAROLD J. HILL. WALTER H. RIGHTER.

CERTIFICATE OF CORRECTION.

Patent ANo. 2,267,525. December 25, 19ML.

EDWARD R. CHILCOIT, ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows; Page 5, seoond column, line l, claim LL, for "sam" read -cam; and that the said Letters Patent should lbe read with this correction therein that the same may conform to the record of the oase -in the Patent Office. Signed and sealed this 17th day of February, A. D. 1912.

Henry Van Arsdale,

(Seal) Acting Commissioner of Patents. 

